Focusing device for electric lamps.



i. C. STEARNS.

FOCUSING DEVICE FOR ELEGRIG LAMPS.

APPLICATION FILED DEC.19.1914.

g, Patented Aug. 17,1915.

.v bayonet slot and spring-pressed plungers for UNITED srnrns ATEN JASON C. STEARNS, OF WORCESTER, MASSACHUSETTS.

FOCUSING 'DEVICE FR ELECTRIC LAMPS.

Specification of Letters Patent.

Patented Aue. i?, 191.5.

Applicatie; filed December 19, 1914. Serial No. 878,104.

tric Lamps, of which the following is a specification.

This invention relates to a device by which an electric lamp can be moved relatively to its reflector for the purpose of flector, and while capable of general use, it

vis especially designed for automobile lamps.

The principal objects of the invention are to provide a device for this purpose in which it is not necessary to hold the lamp bach against a sprii'ig while focusing it, and in which the focusing operation can be performed by simply turning the lamp baci: and forth and applying pressure or pulling on it at the' same time; and also to provide means of such a simple character for accomplishing these results as to greatly reduce the cost of manufacture andl installation and to do away with the spring and helical guide ordinarily used in these devices. Y

The invention also involves improvements in combination of parts and details of construction a-s Will appear hereinafter.

Reference is to be had to the 'accompanying drawings vin which,

Figure l is a side view of a lamp and its I socket member showing the reflector' in position but broken away and illustrating a prefer-red:embodimenty of this invention; Fig. 2 is a longitudinal central sectional view of the same with the parts in another position; and Fig. 3 is a transverse sectional view showing the parts in one position in full lines and in another position in dotted lines.

The invention is shown as applied to a construction comprising a sleeve A on which the mirror B is fixed. This sleeve and mirror ordinarily are secured in the lamp casing in fixed position. In this sleeve is slidably mounted a cylindrical bushing C. rhis bushingconstitutes the socket member for the lamp D and is provided with the usual thispurpose. 'ne of these two membersnis provided with a'longitudinal rack and the "Otlierwith a tooth for engaging the rack2 both located substantially within the cylindrical walls thereof, so as to be simple to -construct and assemble.

rilhe bushing C is shown as provided with a longitudinal rack c formed 'of teeth pressed or cut in its surface and consequently constituting a ratchet member without the necessity of adding an additional member to these parts. It is also shown as provided with 'a' tongue c upset outwardly to forni a j stop. These parts are intended to cooperate bringing it into or out of focus with the rewith certain parts of the cylindrical sleeve A. This sleeve is provided with an integral longitudinal tongue a which is provided with a tooth or teeth a on thc inner surface for engaging the ratchet teeth. This tongue is sprung down inwardly so as normally to come into engagement with the ratchet teeth when, the bushing isturned to the proper position to permit it and when turned to the position shown in Fig. l the teeth ct slide up on a cylindrical surface 02 of the bushing which constitutes means for holding them out of engagement with the rack.

The stop c is vlocated in a rectangularY opening (L2 in the surface of the sleeve A. so that it will stop the circumferential motion vof the bushing in two positions, in one of -which the teeth (if lengage the rack and in the other of which they are held out of engagement with it.v lt also stops the longitudinal motion of the bushin by coming into Contact with the ends-of t ie slot.

The .intermeshing teeth are shown as having radial surfaces on one side for preventing an automatic change inv adjustment when forcing a new lamp into the. socket. The opposite surfaces are conveniently made slanting. This allows outward adjustment without turning the rack out of the way, but this is not usually made use of.

ln the operation of the device it will be noted that when the parts are in the position shown in Fig. l the lamp can be adjusted in and out as far as the stop o will allow. However, people ordinarily iind dificulty in adjusting the lamp in this manner, because after it is started it is natural for it to move to the end of its. range of adjustment and it is diiiicult for an .inexperienced person to stop it at an intermediate point, at least without touching the rei'iector. Therefore, the ordinary way of making the adjustment is to apply pressure and turn the lamp back uit ion, of

f time the teeth e coi e '711e ietchet, the lamp le so as to ip ce or ere is no dangero' i; ovy beyond the point at Wnicii to stopv this wey it will et it is easily adjusted, eithez' by ip rt or by a person entirely 'unfamiliar he construction of tne device, and setuies :ill needs in this respect. Furthermore, `iis construction, 'the use of en additional which is e source of more increase in.

Q'SS

ign,

e device is entiici avoided and at the 'seine 'time the necessity of using a spiral sint is also entirely eliminated. Un account icing awey with these two featurcs,the

cost of the device is ineteiiially reduced Without clucinfg itsie'liciency and in fact with an i :l increase in durability.

ough l have illustrated and described "y aeing'le eniboeliinent ci the invention,

.le l iniettare of the feci that man] modificabe. ine de L L e the art m of the in ei'ein by' any person `lout departing from vention es eXpI-esseci in Thee l (lo not Wish to be cl all the. details of con-struction own and described, but

cio claiin isz-N i focusing e "justing device for an l' con'iprisi, e cylindrical sleeve one n longitudinal rack tooth adapte to engage the l 'teeth being located subo cylindrical Walls of .the

, iin@ being capable inoti n to bring the tooth te analL permit relative longitudinal bushing.

2. in e. clevice 'the cherectcn described, the combination of a sleeve, a bushing slidably mounted in said sleeve and. anpted "so be turned therein, a spring tongue forming a part of said sleeve and having a tooth on the inner side thereof, and a' ratchet -along 'the surface of the sleeve in position to engage With said tooth, saidv bushing having a smooth surface adjacent to said ratchet on which said tooth is adapted to ride up when the bushing is turned to one extreme position, whereby the tooth Will be held out `of engagement with the ratchet and tree adjustment permitted.

' 3. In a focusing and adjusting' device for an electric lainp, the combination With a stationary sleeve having a rectangular slot 60 therethrough, and an integral tongue at one side of said slot provicleoL with teeth on the innerl concave side, and a'bushing mounted in said sleeve and having stop projecting outwardly into said rectangular slot for limiting the longitudinal and circumferential motion of the bushingin the sleeve, said bushingsr having a series of 'teeth on the circuniference thereof in position to be engaged by the teeth on said tongue when 'the bushing is turned to one extreme position, and the bushing being provided with means. for holding the tongue out of contact with 'said y teeth when turned to the other eXtreme posi 75 tion. l

In testimony whereof I `have hereunto set my hand, in the presence of two subscribing witnesses. y 1

' JASON GSTEARNS.

motion of '71e eieeve and Witnesses:

ALBERT FAZ, C. FonPnsT lil/lesson, 

